When Courtney McLean was checking out the dogs available for adoption this week in Tacoma, the first things she looked at were their tails.

That was a lucky break for dogs that happen to be black, such as Matilda, a thin lab mix who happily moved to the front of her pen at the Humane Society for Tacoma & Pierce County.

“I look to see if the tail is wagging, then I look at the facial structure,” McLean said Wednesday. “Color isn’t that big a factor.”

Clearly, McLean hadn’t fallen prey to the Black Dog Syndrome, which applies to both dogs and cats. Whether it’s a stray dog, a new pup or kitten, color does matter to many of those looking to adopt.

“It is true, we have tons of black kittens right now,” said one shelter assistant with Puyallup Metro Animal Services/Adoptions. “ People like a lot of color. Black cats and dogs have to sell their personalities.”

The Black Dog Syndrome is nothing new. Those who work with animals have seen it for decades.

“I have been doing animal rescue for 20 years, and it’s always been a factor,” said Carina Collard of Dog Rescue Washington. “Originally, it seemed to be just big black dogs, now it’s black animals in general.

“I’ve had a black chihuahua available for weeks. She’s sweet — a perfect little dog — and people don’t even seem to notice her. We’ll have an adoption event somewhere, and at the end of the day, there are always black dogs and cats left.”

It seems that the Internet — where animal rescue sites can now display the photo of every dog and cat available —has fed the syndrome.

Marguerite Richmond, a local Humane Society executive, owns a black dog herself, and may have discovered one of their problems.

“I took his picture in front of the Christmas tree and it was like he completely disappeared in the photograph,” Richmond said. “There was the outline of the tree, and this great black hole in the center.

“It’s harder to get a good photo of a black dog.”

There have been studies, surveys and tests, and no one can completely explain the syndrome, though plenty of theories exist.

“I think people gravitate to exotic looks, and black dogs aren’t exotic,” said Kelly Nelson of Kindred Souls Foundation in Tacoma. “There are superstitions about black dogs and cats. It’s just this weird phenomenon.”

Richmond thinks it has far more to do with people than animals.

“Maybe it’s a brain chemistry thing,” she said. “Our brain is drawn to the colorful, so our eyes land on the lightly colored dogs and cats. If you like making eye contact, it’s easier with an animal with light-colored eyes.

“You get a beautiful black lab with big brown eyes, it’s like they almost disappear at first glance.”

When Josh Korbal went looking for a dog this week, he had two requirements.

“I wanted a big dog, and it had to get along with my two-year-old daughter, Haleigh,” he said. “I talked it over with the Humane Society staff and they thought they had a couple of candidates.”

One was a good-sized pit bull mix, black with a few white spots.

“The color never crossed my mind,” Korbal said. “He was great with Haleigh, gentler than he was with me. He’s got a new home now.”

Adoption agencies are delighted with people like Korbal, but they have to pitch their black animals to those for whom color is a first-impression factor.

Dog Rescue Washington, for instance, puts colored hair ties on their black dogs and cats when they have an adoption event.

At the Humane Society, Richmond said the staff has come up with efforts that help battle Black Dog Syndrome.

“We try to keep them in separate pens, because black dogs and cats have trouble standing out in a pen with other animals,” she said. “We put colorful bandanas on them, try to make their faces pop a little.

“The thing is, so many dogs sell themselves if they can get into a room with someone. Our challenge is to give black dogs and cats an opportunity to make enough of an impression that they can reach that stage.”